Since interest of researchers in entrepreneurial success is growing incessantly, the need for methods allowing quantitative measurement of this phenomenon through the development of a tool having the psychometric parameters of accuracy and reliability becomes more and more pronounced. Therefore, there are pilot studies on the Questionnaire of Entrepreneurial Success in progress, which examine a new tool enabling accurate and reliable quantitative measurement of entrepreneurial success. The present report elaborates on the initial findings regarding theoretical accuracy of the Questionnaire of Entrepreneurial Success. The first part of these findings was already presented in the article “Questionnaire of Entrepreneurial Success – Report on the Initial Stage of Method Construction.” The study was carried out in Poland and examined 144 entrepreneurs running a business in various voivodeships for at least 4 years. The following tools were employed: The Questionnaire of Entrepreneurial Success (QES), Achievement Motivation Inventory (AMI), General Self-Efficacy Scale (GSES), Entrepreneurship Efficacy Scale (EES), and the Self-Esteem Scale (SES). This part of the study was intended to demonstrate the character of the relationships between entrepreneurial success and achievement motivation. In the course of the study, significant correlations between entrepreneurial success and achievement motivation were revealed (e.g., Flexibility, Courage, Faith in success, Dominance, Preference for difficult tasks, Independence, and Objective orientation); thereby confirming the theoretical accuracy of the Questionnaire of Entrepreneurial Success. Further in-depth correlation analysis led to the conclusion that the adopted perspective on entrepreneurial success modifies these correlations (i.e., short-/long-term subjective perspective and short-/long-term objective perspective). The achievement motivation dimensions of Elasticity and Dominance were found to correlate with entrepreneurial success (from each of the four perspectives separately). The results of comparative and profile analyses showed that entrepreneurial individuals demonstrating high entrepreneurial success obtained higher scores in AMI, EES, SES, and GSES. Furthermore, significant differences were revealed in terms of flexibility, dominance, self-esteem, effectiveness of gathering market information, business entrepreneurial efficacy, and generalized sense of self-efficacy (compared to entrepreneurs showing low entrepreneurial success). The initial pilot study examining the Questionnaire of Entrepreneurial Success supports the claim that the tool has good psychometric parameters.